1. Field of the Invention
The present invention relates to an exercise wheel that may fix the travel thereof and prevent damage resulting from reverse rotation of torsion springs.
2. Description of the Related Art
FIGS. 5 through 7 of the drawings illustrate a conventional exercise wheel that includes a housing 20xe2x80x2, a main gear 43xe2x80x2, two wheel pairs 30xe2x80x2, and two grip rods 50xe2x80x2. The housing 20xe2x80x2 includes a compartment with a downwardly facing opening and aligned holes 26xe2x80x2 on two sides thereof into which the grip rods 50xe2x80x2 are mounted. Two stop rods 21xe2x80x2 are mounted inside the housing 20xe2x80x2. One of the sides of the housing 20xe2x80x2 has a hole 22xe2x80x2 and two positioning holes 23xe2x80x2, and two notches 24xe2x80x2 are defined in a lower edge of the side of the housing 20xe2x80x2.
A main stem 251xe2x80x2 of an adjusting member 25xe2x80x2 is extended through the hole 22xe2x80x2, a positioning peg 252xe2x80x2 of the adjusting member 25xe2x80x2 is extended through one of the positioning holes 23xe2x80x2, and a stop stem 253xe2x80x2 of the adjusting member 25xe2x80x2 is extended through the notch 24xe2x80x2. A spring 254xe2x80x2 is mounted around the main stem 251 xe2x80x2 for biasing the adjusting member 25xe2x80x2.
A main shaft 40xe2x80x2 is extended through aligned holes 26xe2x80x2 in the housing 20xe2x80x2 and the main gear 43xe2x80x2. Two torsion springs 42xe2x80x2and 44xe2x80x2 are mounted on both sides of the main gear 43xe2x80x2 and around the main shaft 40xe2x80x2 and an end cap 41xe2x80x2, 45xe2x80x2 is mounted to each outer end of the main axle 40xe2x80x2. Each wheel pair 30xe2x80x2 is mounted in the housing 20xe2x80x2 by an axle 27xe2x80x2 and includes two rollers (not labeled) connected by a shaft (not labeled) that has teeth 31xe2x80x2 formed on an outer periphery thereof for meshing with teeth (not labeled) of the main gear 43xe2x80x2. Each torsion spring 42xe2x80x2, 44xe2x80x2 includes a first end 421xe2x80x2 securely attached to an associated stop rod 21xe2x80x2 and a second end 422xe2x80x2 securely attached to the main gear 43xe2x80x2.
When in use, the user bends downward and grasps the grip rods 50xe2x80x2 attached to two ends of the main shaft 40xe2x80x2 to make the wheel pairs 30xe2x80x2 roll on the ground. During rolling of the wheel pairs 30xe2x80x2, the torsion springs 42xe2x80x2 and 44xe2x80x2 are tensioned by the main gear 43xe2x80x2 via transmission by the teeth of the main gear 43xe2x80x2 and the teeth 31xe2x80x2. The second end 422xe2x80x2 of each torsion spring 42xe2x80x2, 44xe2x80x2 bears against and is thus stopped by the stop stem 253xe2x80x2 of the adjusting member 25xe2x80x2 to thereby limit the forward travel of the exercise wheel.
Nevertheless, when the user operates the main gear 43xe2x80x2 in the reverse direction, the torsion springs 42xe2x80x2 might be damaged, as the torsion springs are twisted in the wrong direction, as shown in FIG. 8.
It is an object of the present invention to provide an exercise wheel that may limit the forward travel of the exercise wheel.
It is another object of the present invention to provide an exercise wheel that may prevent damage to the torsion springs when the exercise wheel is operated in the wrong direction.
In accordance with a first aspect of the invention, an exercise wheel comprises:
a housing having two sides;
two grip rods secured to the two sides of the housing, respectively;
a chassis housed by the housing and including two first stops each having a first side and a second side;
a main shaft supported by the chassis;
a main gear mounted around the main shaft and including a second stop;
two wheel assemblies rotatably mounted to the chassis and each including a shaft with a toothed portion for meshing with the main gear; and
two torsion springs mounted around the main shaft and respectively located on both sides of the main gear, each said torsion spring including a first end securely attached to the chassis and a second end securely attached to the main gear;
wherein the second stop of the main gear bears against the first side of each said first stop of the chassis when the exercise wheel is in an initial state, thereby preventing rotational movement of the exercise wheel in a reverse direction; and
wherein rotational movement of the exercise wheel in a forward direction is allowed until the second stop of the main gear is stopped by the second sides of the first stops of the chassis.
The main gear further comprises a peripheral stop surrounding at least one of the torsion springs to thereby avoid radial outward expansion of the torsion springs. The first side of each second stop of the chassis comprises a buffering portion.
In accordance with a second aspect of the invention, an exercise wheel comprises:
a housing having two sides;
two grip rods secured to the two sides of the housing, respectively;
a chassis housed by the housing;
a main shaft supported by the chassis;
a main gear mounted around the main shaft;
two wheel assemblies rotatably mounted to the chassis and each including a shaft with a toothed portion for meshing with the main gear; and
two torsion springs mounted around the main shaft and respectively located on both sides of the main gear, each said torsion spring including a first end securely attached to the chassis and a second end securely attached to the main gear;
the main gear further comprising a peripheral stop surrounding at least one of the torsion springs to thereby avoid radial outward expansion of the torsion springs.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.